Title: Addressing Challenges of Cutting Natural Stone Panels: Integrating Overcuts into a Mathematical Programming Model for 2D Rectangular Cutting Problems

Speaker: Maria Antónia Carravilla

Summary:

In the industry of ornamental stone, the process of cutting natural stone involves solving a two-dimensional cutting problem. Apart from the typical constraints found in cutting and packing problems, this industry faces additional limitations due to the characteristics of the raw material and cutting technology, which distinguish it from other industries.

The specific problem we will address is the cutting of stone panels. Geometrically, these panels can be treated as irregularly shaped two-dimensional objects with certain defects. They are considerably thick and heavy compared to the materials commonly discussed in literature, and the cutting process is performed using a saw, requiring guillotineable patterns. The thickness of the stone, combined with the circular saw technology, results in an effect known as overcut. Overcut refers to a cut that extends beyond the edge of the intended piece. This effect introduces non-trivial constraints on cutting models and algorithms. Alternatively, the cutting machine can utilize a suction lifter to lift and partially deflect the sheets, avoiding overcutting. However, this operation consumes two important resources, time and energy, and its cost must be weighed against the cost of waste generated by cutting the pieces separately on the cutting plane.
In this presentation, we will first focus on introducing and formally defining these specific constraints and objectives. We will support our explanation with videos, photographs, and real cutting plans from the stone industry, which will help illustrate the unique aspects of this cutting and packing application. This, in turn, may inspire innovative research to address its distinctive characteristics.
Subsequently, we will present a mathematical programming model based on the “floating cuts” MIP model used for two-dimensional guillotine and non-guillotine cutting problems. We will introduce additional constraints to account for the overcut phenomenon. To the best of our knowledge, this particular constraint has not been explicitly addressed in the existing literature and poses a non-trivial challenge to tackle.

Finally, we will discuss some computational results obtained from applying this model in practice.

Biography:

Maria Antónia Carravilla is an Associate Professor and Director of the Doctoral Program in Industrial Engineering and Management at the University of Porto’s Faculty of Engineering (FEUP). She is also a Senior Researcher at INESC TEC and a lecturer at Porto Business School (PBS). Her expertise lies in Operations Research (OR), where she focuses on solving real-world problems in industry, services, and public administration. Her research primarily revolves around integrated production problems, like logistics, vehicle routing, cutting, and packing, with a particular emphasis on resource optimization. She has made significant contributions to the field through innovative Metaheuristic approaches and their integration with Mathematical Programming methods. She has collaborated on various projects with industry and institutions, producing valuable decision support systems and analysis reports. Additionally, she has actively contributed to a project involving evaluation of primary and secondary schools and the development of an Education Observatory in Portugal. Her dedication to teaching is evident through her supervision of numerous master’s theses and pedagogical projects. With a strong publication record and leadership in research projects, Maria Antónia Carravilla has an impact on the field of Industrial Engineering and Operations Research, both nationally and internationally.

MEETING ID: 873 1557 5255; PASSWORD: 778635

WED 9 August 16:00-17:00 (AEST, Melbourne Time) – online only